1. Field of the Invention
The invention relates to a knee airbag device.
2. Description of the Related Art
Japanese Patent Application Publication No. 2002-37003 (JP-A-2002-37003) describes a knee airbag device that includes an airbag module fixed to a column tube inside a column cover that covers a steering column. Airbag doors are provided in two portions (right and left portions) of the column cover. When a knee airbag is deployed, tear portions are torn, and thus, the airbag doors are opened toward right and left sides. As a result, two openings (right and left openings) are formed in the column cover, and the knee airbag expands radially around the steering column, that is, toward areas on right and left sides of the steering column through the openings.
However, in the above-described conventional knee airbag device, it is difficult to quickly deploy the knee airbag toward the areas on right and left sides of the steering column, while satisfying requirements regarding the stiffness, serviceability, cost, and weight of the column cover, and easiness of assembling the column cover.